With regards to EZY, I wouldn't say their EMA operation flopped. They just did their usual tactic of shying away from the competitors in that market, FR and WW (BmiBaby) as was at the time.
They reallocated their three based aircraft citing stagnation of the EMA base and better growth opportunities elsewhere. If only they'd stayed put things may have turned out different for them following the demise of WW only 2 years after.
I think based on broadly the same reasons with stronger market positions held by rival carriers, it would be unlikely for EZY to set up a BHX base, though some of the commercial decisions they seem to take regarding their route network never quite cease to surprise me.